Girls in Chess

I devoted a chapter of King’s Gambit called “Female Counterplay” to women in chess, and I quoted the statistic that 10 percent of U.S. tournament chess players are female.

Now Susan Polgar, former women’s world champion and current chairman of the United States Chess Federation, reports female participation by age in her blog. The statistics confirm the oft-made observation that girls starts off strong in scholastic chess but quit the game as they get older:

Ages 12 and below: 5,491 of 29,791, or 18.4%
Ages 13-15, 1121 of 9,031, or 12.4%
Ages 16-19, 629 of 6,771, or 9.3%
Ages 20-24, 129 of 2,208, or 5.8%
Ages 25-64, 1,085 of 28,932, or 3.8%
Ages 65 and up, 23 of 2,172, or 1.1%

2 Responses to “Girls in Chess”

The “oft-made observation” may be true, but, speaking as a professional data analyst, I have to point out the statistics you present don’t actually confirm it. What you are proposing is an “age effect” explanation – that is, that as females get older they quit the game. There are, however, other kinds of explanations that would explain the data equally well. One of them is a “period effect” explanation – to put it simply, that “times have changed”.

The USCF members aged 20-24 were born in the years 1983-1987 and probably learned the game in the years 1989-1993, more or less. The USCF members aged 16-19 were born in the years 1988-1991 and probably learned the game around 1994-1997. Well, did things change for girls and for women in chess and in life in general during that period in such a way as to bring a lot more girls into the game? Arguably so.

It might be – as far as these numbers go – that what has happened is that more girls have been brought into chess in recent years, and that boys and girls will quit the game at equal rates, and that four years from now the Age 20-24 group will be 9.3% female as the Age 16-19 group is today.

This doesn’t mean that I think the age effect explanation is wrong, it only means that this one table assembled at one point in time (a “cross-section”) aren’t enough to decide between it and a period effect explanation or (possibly most likely) a combination of the two. If we can look at a set of ten comparable tables assembled over the years 1998-2007, that would go a long way to answer the question. Better yet would be an assemblage of data about individual players over time.

He’s right. The most direct way to prove the hypothesis is to track random sub-populations of girls and boys born in the same year (cohorts) to see when they pick up chess and when they drop it. If we do this across multiple cohorts over time, we will see if the hypothesis is true now and what the trends are. Pete – I like the cut of your jib.